Revy-Saerang-Analytical- Problem- Titanium Dioxide in Masterbatch
Titanium Dioxide is a natural chemical that is used extensively in agriculture, cosmetic, food and coloring industry. Titanium dioxide, when used in colored industry, is an inorganic white pigment that is largely consumed in the coloring industry to enhance the opactiy, the whiteness and to achieve a desirable visual impact.(2)
The special chemical and physical features of Titanium dioxide as an inorganic white pigment are incorporated with other ingredients such as additives, colored pigments and resins in colored masterbatch production (masterbatch is a high concentrated pigment carrier for food & beverage packaging, cosmetic packaging, computer hardware production, etc) production. (1)
My interest is to recognize the nature of titanium dioxide in causing the coloration on color pigmented carrier (masterbatch) for plastic to be non-reproducible for one production to the next. When this happened, the quality control lab has to reformulate a more stable formula and remixing product has to be done.Reformulation is ideally to be avoided because it increases the capital cost of production for each batch and it influences customers' satisfaction on products made by the company. Through analytically studying the effect of titanium Dioxide in masterbatch, a method of study or a new technique could be devised and implemented to improve the production process of both white and colored masterbatches.(3)
My hypothesis is that titanium dioxide being larger in particle in comparison to other components in masterbatch formulation has lead to non-homogeneity of mixing and to cause a hindrace of pigment dyability in colored masterbatch production during coloration and pigmentation.
The analyte that I will focus on is Titanium Dioxide and it could be found in the mixture components of polymer resin, additives (antioxidants, Silicon oxide) and other inorganic pigments.
UV-Vis absorption spectrometry
The range of wavelength of titanium dioxide can be related closely to the preparation method of titanium oxide itself. For titanium dioxide with a commercial name Degussa P25 titanium dioxide (consists of 80% anatase and 20% rutile) that have been chemically treated with polymer compositions, it is found that the wavelengths of absorption for my analytes ranges from 400 to 600 nm. It is important to consider that this absorption spectra may be differed if some methods are not implemented when measurements are made such as the analyte has to subjected to low-temperature heat treatment above 350 K and making BaSO4 as a reference standard to the spectometer. (4)
Unfortunately, I could not find an optical density of my analyte within the wavelength range that I found from 400 to 600 nm. However, I found in source (5) that at wavelength 310 nm, titanium dioxide has an optical density of 0.8785. This data was found from a research paper that focused its interest of particle size measurement of titanium dioxide in safety of efficacy of nanotechnology.
In doing a research about UV-Vis absorption spectroscopy, I learnt that it will be a brilliant idea to narrow down my analytical problem to a particular method. So while finding more resources and getting more information from the class, I will attempt to assume that my analyte is prepared similarly with source (4).
Similiar Analytical Problem(s)
Exposure to Zinc Oxide and Titanium Dioxide Nanoparticles in Sunscreen by Heidi Nelson Heidi talks aboout the commercial uses of nanoparticles in sunscreen and its impact on human health and the environment. Her central hypothesis is to determine whether or not nanoparticles could be detected in blood or only present at the top layer of the skin after sunscreen's application on human's skin. The analytes for her analytical problem will be both zinc oxide and titanium dioxide nanoparticles and the matrix will be human skin and body. Other than the fact that we both focus on similiar analyte, I think my analytical problem mainly focus on particle size of the analyte and the optical properties that it has such as scattering of light, dispersion, etc.
For both our analytical problems, the optical properties of nanoparticles relate closely with a particle size and distribution, it is important to separate these nanoparticles by size and then measure the concentration according to the signal response making use of calibration curves. With these measurements, multiple sampling will help me to calculate and analyze the particle size distribution and how the content of TiO2 as our analytes. For my anaytical problem, I could analyze the deviation of other pigments and additives to mix homogenously and reproduce similar masterbatch production with both standard or previous masterbatch production.
In comparing the differences of studies between my analytical problem and Heidi's, it is important to recognize the matrix which in Heidi's case will be the human skin and the blood where in my case will be polymer resin or other pigments. With this being said, I think Heidi has to do separation before collecting the UV-vis spectra because she is dealing with analyte in more delicate yet complex matrix system. As for me, I will separate my analyte using a normal chromatography method to separate the nanoparticles and get a number to find the nanoparticle concentration later by using UV-vis.
Ahmed, S. I., Shamey, R., Christie, R. M. and Mather, R. R. (2006), Comparison of the performance of selected powder and masterbatch pigments on mechanical properties of mass coloured polypropylene filaments. Coloration Technology, 122: 282-288. doi: 10.1111/j.1478-4408.2006.00042.x (1)
Fisher, J. and Egerton, T. A. 2001. Titanium Compounds, Inorganic. Kirk-Othmer Encyclopedia of Chemical Technology.(2)
Russell, S. (2005) Color Compounding, in Coloring of Plastics: Fundamentals (ed R. A. Charvat), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/0471721581.ch18(3)
Vyacheslav, N. and Serpone, N. (2006) Visible Light Absorption by Various Titanium Dioxide Specimens, American Chemical Society. Russia. doi:25203 (4)
Delrieu, P. Particle Size Measurement of Attenuation Grade Titanium Dioxide in Diespersion and Sunscreen Lotion, Kobo products(5)
Blog 6- Chemical Structure and Standards
2. The chemical structure of my analyte, Titanium Dioxide (rutile form) is:
(accessed on October 24, 2011)
3. Information about my standards:
Company name: DuPont
Catalogue number: DuPont R-104 titanium dioxide
Quantity: 25 kg (packaged in polyethylene bag)
Price: Not available online (Need to contact local agent)
(accessed on October 24, 2011)
Blog 7- Atomic and Mass Spectrometries
The analyte that I will be looking for spectrometries will be Titanium dioxide. I think atomic spectrometries can be used to quantify the analyte of my analytical problem, however considering the preparation of analysis and a method to convert solid sample into solution suitable for analysis could be very time-consumptive and it also limits to eliminate the particle size effect application of titanium dioxide. Based on one study I found, ICP-OES/MS can be employed using slurry nebulization and electrothermal vaporization to deal with solid sample, therefore this will be desirable for my analytical problem in excluding out all the impurities before quantifying the concentration of titanium dioxide.
JOURNAL OF MASS SPECTROMETRY
J. Mass Spectrom. 2006; 41: 1378-1385
Published online 29 September 2006 in Wiley InterScience
(www.interscience.wiley.com) DOI: 10.1002/jms.1111
Blog 11. Capillary Electrophoresis Techniques
1. Capillary Zone electrophoresis is only good to separate ionic species based on their charge, where MEKC (Micellar Electrokinetic Chromatography) is mostly used to separate DNA and proteins (or biomolecular compounds). Capillary Isoelectric Focusing Electrophoresis) is done based on the isoelectric measure or pH of the analyte. Due to this reasoning, the best separation technique of CE would be CGE (Capillary Gel Electrophoresis).
2. The type of capillary electrophoresis that is most suitable to separate my analyte from other matrix components in my sample is Capillary Gel Electrophoresis (CGE). This is because all other CE techniques separates the components based on charge of the analyte. On the other hand, CGE allows separation to occur based on particle sizes and multiple particle shapes and since my hypothesis require me to test on parameters like particle distribution and particle size, CGE will be a good technique in analyzing my analyte in matrix. It also allows me to do multiple runs in parallel on the same gel with optimized conditions.
3. Suitable conditions of using CGE as a technique:
Buffer composition:0.5x TBE (Tris-borate EDTA buffer)
Electric field used:150 V
Capillary type: Coating of 100% SH-PEG-COOH
4. I would use a Transmission Electron Microscopy for my detector. It is because electrophoretic mobilities can be quantitatively measure based on the gel mobilities of polymer coated nanoparticles and an image of the interacted electrons transmitted could be obtained to detect this phenomenon.
Separation of Nanoparticles by Gel Electrophoresis According to Size and Shape
Matthias Hanauer, Sebastien Pierrat, Inga Zins, Alexander Lotz, and Carsten Sönnichsen*
Institute for Physical Chemistry, University of Mainz, Jakob-Welder-Weg 11, 55128 Mainz, Germany